Preparation of liquid fertilizers with improved storage properties

ABSTRACT

a method for improving the storage properties of liquid fertilizers made from wet-process phosphoric acid. The wet-process acid is essentially defluorinated so that when it is processed by ammoniation to make high-analysis ammonium polyphosphate liquid fertilizers, the sometimes almost immediate precipitation of undesirable sludge compounds of magnesium does not occur in the liquid over long periods of storage. The liquids may be produced by dissolving hot ammonium polyphosphate melts directly as it is produced or by dissolving dry granular solid ammonium polyphosphate made from this type acid. 
     Both ammonium polyphosphate and urea-ammonium polyphosphate base solutions made from defluorinated wet-process acid are highly stable and they exhibit increased tolerance for higher magnesium and lower polyphosphate levels.



